UPDATE: I have now posted some additional thoughts about this issue.
It’s been a frustrating time here at the hotel in Ontario, CA, where all I’ve been trying to do is use the Internet connection. I’m staying at the Best Western and did so largely because they advertised free high-speed Internet (they were also cheaper than others). First annoyance was discovering that I was too far away from their APs to use wireless, but since I had an ethernet cable I just plugged into the wall jack and expected to get access. The very first time I connected, I did get an IP address and could see an entry in my routing table for the default gateway. However, I couldn’t ping it.
Being rather used to network troubleshooting, I did the usual things… bringing the interface up and down, disconnecting and re-connecting the cable. I even went to the hotel lobby and got a new cable in case the issue was with my portable/retractable cable.
Nothing. No net.
In desperation I did the thing that tech support always tells you to do but I avoid… reboot. Nothing.
So finally this morning I got on the phone to the Best Western tech support and after waiting, oh, 20 minutes or so I got through to a tech and ultimately we figured out the problem:
Skype!
More specifically, all the bizillion connections that Skype was making out into the P2P cloud. The tech reset the switch and asked me to connect again and his immediate response was “Whoa! Something on your computer is generating an incredible number of sessions out to the Internet! You are tripping our filters and it is blocking out your MAC address.” With him on the phone, we tried some experimentation. I shut down Skype, at which point he said I was generating much more normal traffic. As soon as I launched it again, he noticed a very large jump in the number of session connections I was establishing. He said it was something like 396 sessions he was seeing coming from my computer. He also said that I’ll keep being locked out of their system if I keep Skype running.
So I shut down Skype. Which, of course, is annoying. Part of why I wanted to use the high-speed Internet is to use Skype for IM and for voice/video calls.
I find it a bit odd that Skype was generating so much extra traffic, but then again I am pretty much always connected into several persistent group chats and had maybe 8 or 10 individual chat windows still open that I’d left open from when I’d last been chatting with the person. (The Mac Skype client makes this easy to do, but I’ll write about that sometime.) The persistent group chats, especially, do generate a good number of connections as they link out into the P2P cloud. Perhaps if I closed all of those windows and killed off all my individual chat windows Skype might have behaved better. (Or perhaps not, I might have had to leave the persistent chats in order for Skype to stop making those connections.) I don’t want to try it out, because I do want to keep my Internet connection up right now.
In any event, should you be at a hotel and find yourself unable to connect… it might be a P2P app like Skype tripping off the hotel’s filters and blocking your access. Fun, fun, fun….
I’ve had the same thing happen to me at a hotel, during CES 2007, no less. The thing I find strange is that it isn’t the bandwidth volume that triggers their alarm but the number of sessions. Skype has a zillion small sessions that can look like the beginning of port scanning or a bot-gone-wild. Skype pings your contacts for presence, updates its cloud connections, checks for updates to recent chats, etc. The problem isn’t Skype, of course, it’s the guardians of hotel networks. They’ll fix it when they start using Skype themselves.
It seems that the HOTEL’s IT dept./subcontractor needs to be able to determine – ‘Oh, it is merely Skype being used by a patron’ and permit it to pass properly, no?
I am usually starting the troubleshooting with Wireshark.
It helps a lot!
@Phil – Interesting. I haven’t (obviously) stumbled upon this issue before. You’re right that a Skype launch could look like some kind of attack if it is sending out all those different connections.
@Phil, @Marc – yes, it’s an issue that hotel IT dept’s will need to come to terms with over time as more P2P apps that have similar behavior are in use.
@Jozef – Yes, Wireshark is a great tool. I probably would have tried it but I was not seeing any network connection at all. So I didn’t think I was at the point where Wireshark would have helped.
Thanks for all the comments.
Wow! I’m not sure if I should be the one apologizing for all this (though I don’t think the pacificIT public Skype chat generates THAT many connections!). Excellent piece Dan and a good heads up when things aren’t connecting correctly from a public access space. Congrats on being picked up on Techmeme as well!
Yup. Skype can be a bandwidth hog, even when you’re not signed in and have the small icon still in the system tray.
Whenever I have network clogging going on at home, Skype is always the first thing I shut down ‘completely’ on all machines. Seems to work.
i just had a version of this problem on my home cable internet connection. In my home television, phone and internet all from the same cable provider (Charter). tried a number of things to regain service and eventually set up a service call which i have to pay additional for. The moment i quit skype the problem vanished. I had no chat windows open and had not used skype in over a week. I’m starting to worry about skype and the resources it requires and increasingly uncomfortable with who might have access to my computer and my connection in the background. Why is skype generating so much traffic when i’m not using it?
PING:
TITLE: Another Hotel Fails To Support Skype – Here’s Why Skype’s P2P Connection Model Breaks Their System
BLOG NAME: Disruptive Telephony
Summary: Hotels restricting the number of simultaneous network connections per user may wind up blocking legitimate usage of Skype. Skype’s peer-to-peer network model uses a high number of network connections to synchronize multi-party group chats. Rea…
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TITLE: Blue Box #68: Top 14 VoIP Vulnerabilities, Asterisk security, VoIP hacker, IMS, P2P, Skype, industry moves, VoIP security news, listener comments and more…
BLOG NAME: Blue Box: The VoIP Security Podcast
Synopsis:Blue Box #68: Top 14 VoIP Vulnerabilities, Asterisk security, VoIP hacker, IMS, P2P, Skype, industry moves, VoIP security news, listener comments and more… Welcome to Blue Box: The VoIP Security Podcast #67, a 46-minute podcast from Dan York…
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TITLE: Skypespam – here it comes
BLOG NAME: broadstuff
Until recently my worst Skypespam was a Latvian “Escort” who started a call in the middle of a presentation, but now I’ve had variations of this note below over the last few weeks – if you have too, don’t click on it – its spam, scam and potentially malwa
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TITLE: Additional thoughts on Skype and hotel networks – there’s issues on both sides…
BLOG NAME: Disruptive Telephony
To my immense surprise, my article yesterday about my challenges with Skype and my hotel Internet connection just hit TechMeme today, so welcome, anyone who is coming my way from there. But that also prompted me to want to offer
‘NetLimiter'(http://www.netlimiter.com/) allows you to ‘limit’ or shape the bandwidth a given app can make use of. Might be worth investigating.
I for one am not surprised. If I was a network admin, would I want to let Skype take over my network?? The same for any other P2P application.
For business users this is just another reason (the recent outage and Skype worm are a couple more) not to use Skype. Why would I want to use Skype when there are plenty of other IM services out there? Beats me…
This is not surprising. Whenever you have Skype open (and logged in?) you are part of the Skype peer-to-peer network. Skype can use your computer as a relay for other people’s traffic. That’s what “peer-to-peer” is all about.
Closing all chat windows, etc won’t help. Basically, when Skype is open, you’re their bitch.
Sounds like you might be running as a supernode. Did you try the registry hack which disables this functionality?
http://www.skype.com/security/universities/
@Marc – thanks for the pointer to netlimiter. I don’t know if it would have helped but it sounds interesting to check out.
@Moshe – There’s a host of reasons why I actually prefer Skype for business communication over the other IM services, but I should probably detail that in a separate message. One of the major reasons is the sheer size of the existing directory, i.e. the people I want to connect with are already using the service. But I’ll elaborate in another message.
@Tom and @Jim – I don’t believe I was functioning as a supernode (and thereby relaying other people’s traffic). If you look at the second item in the link that Jim provided (“How can we prevent our network from hosting supernodes?”), Skype has always been very clear that if you are behind a NAT device / firewall you will not be a supernode. This makes sense with the architecture. You need the supernodes to be on publicly accessible IP addresses where other Skype users can reach them from behind NAT devices. So as long as you are not publicly-accessible, you should be fine. In my case, I was getting a private RFC1918 address (10.x.x.x) and was very clearly behind a restrictive firewall.
I think the issue probably was what Phil Wolff mentioned – all the connections Skype needs to make to update presence, connect into chats, etc. I have something like 150 contacts in Skype. I am in several persistent group chats that have over 100 people each in them. When Skype launches, it does need to update the presence info on all of those various people and so it makes sense it would launch tiny connections into the cloud. At some point I’d love to spend some time doing some traffic analysis on it (yes, I *am* a network geek), but that would seem to be a plausible explanation.
Thanks for all the comments.
Skype, Limewire, MySpace, Kazaa – High Session Traffic Blockage at Hotels- I happened to run across your issue “Skype” issues complaining about being taken off the Internet at the Best Western in Ontario. i can offer you and anyone reading this “the other side of the issue.” There are always two sides to every story and this is what we deal with from the “Tech support” and hotel ownership side when it comes to Internet Service at hotels, whether they are free or $14 a night.
What you do at your home is totally up to you and you should be able to run any web based site or application you want, as long it meets with the terms and conditions of your carrier, Cox, Time Warner etc.
When you are in a hotel, you also agree to abide by their terms and conditions. You need to understand that the hotel has an objective to provide services for the benefit of all their guests and keep their service up and running as best they can; their rankings now depend on it.
“In the old days,” when users would access Skype, Limewire, multi user war games or get a virus from MySpace or thier carrier, the Internet at that property would come to a sreaching halt and the tech support staff would have no alternative but to reboot the Internet router. That would usually last about 15 minutes or until someone overan the buffers in the router and caused an internal denial of service and or if the carrier detected the high session traffic, they would shut the internet connection down. Time Warner and Cox will do this within hours.
Along came some new products from Nomadix, IP3, Cisco, and some other hospitality gateway companies whose sole purpose was to keep the Internet from crashing.
Session Traffic and Mac Filtering tools were implemented in these gateways and now you could keep people who had no idea what their computer was doing in the background from clogging up the Internet.
Now, for the benefit of the larger majority and for those business people whose primary need is basic email and web browsing, the internet stays up and running.
Only those abusers using Skype, Limewire, Kazza and those who might bave a virus or Trojan horse are taken off the net, leaving the Internet up and running for the rest of the hotel’s guests.
As a support services company, dealing with an individual is far easier than dealing with 30 ro 40 people who cant get on line and would complain to the corporate office that they had no Internet service.
Hotel owners have decided that dealing with an abuser (who agreed to abide to their hotel’s T&Cs,) is far better than dealing 40 or 50 people nightnly causing their rating to go down.
So while Skype is free, it also has its drawbacks, it creates high session traffic which left unchecked would eventually consume the hotel’s Internet connection leaving everyone in the dark.
Most Best Westerns, Ramada Hotels, Holiday Inn Express, Marriott, Hilton, Emabassy Suites and many others have deployed these gateways which are in place to provide service for those who can live within the T&C’s even if they dont understand them or realize that use of things like Skype violate those T&C’s and jepardise the connection for everyone else.
We consult with many hotels and unfortunately for unknowing end users, this is the position most have taken as an alternative to loosing their connection and having everyone call the front desk complaining.
Most gateways are set at 200 to 300 session limits per minute. If you hit that number, they capture your MAC address and then block the connection to your computer and or router if you were so inclined to use one (also a violation of the T&C’s)
Every once in a while we get weak and let someone through or take off the session locks. In all cases, we always remember shortly thereafter why the rules are put in place when other guests call complaining the network is so so slow and then shuts down.
Complain all you want, but with cell rates so cheap these days, you should be using your cell with unlimited calls after 7PM for free where it wont boot you off.
WiFi-PS is a National Hotel Support company with 20 years experience in this business. Look up “wireless hotel support services” or “guest internet support services,” on Google and you’ll find us. We are usually ranked around Number 1.
Adam,
Many thanks for your detailed reply. As someone who works with Internet / network security, I do completely understand the necessity to ensure that the hotel’s Internet access stays operational. As a frequent business traveller who relies on high-speed Internet access at hotels, I’m very grateful for companies like yours and the products you mention.
Having said that, I do *not* place Skype in the same category as file-sharing services such as Limewire and Kazaa. As Skype themselves note, somewhere around 30% of their users are business users. For me it is an IM and voice client that is used to communicate with, in many cases, business clients.
I would also note that in all the time before that stay in Ontario, CA, and since that time, I have not been blocked from using Skype at any other hotel. This includes Hiltons, Marriotts, other hotels and the Westin where I am currently staying.
Again, thank you for your reply,
Dan
Adam,
Welcome to the 21st century. It’s 2007, not 1999.
Afraid I’m with Adam. If Skype can open dozens or hundreds of connections on launch based on last state it’s a badly-behaved network program, end of story. Worse when run over a connection shared with dozens of other people, including business people.
Would you do the same thing driving on the streets or going through a door with other strangers? No, of course not.
Instead deploy some 21st century manners when you use Skype in those cheap hotels which give you free (free – for heaven’s sake!) broadband.
Interesting comments about Skype. A better solution would be T1 internet access because it will provide a superior internet connection.
As the end technician that you talk to that says, “Oh, hey it looks like you have been blocked from using the system.” I would very much like to voice my opinion about this. Having read through all of the comments I would have to say that there needs to be a middle ground to settle on. Yes Skype can be very useful and handy especially for you business people. In addition to that yes there are other people you are sharing the connection with.
As far as lumping it together with programs like Lime wire an Kazaa I would be more likely to lump it in with Utorrent bittorrent an viruses. The traffic across the servers that all of these programs pass is horrendous. Having said that, the one program that stands out from the others is in fact Skype. Why? Because a guest using Skype can be limited down to 1 k, YES 1 kbs!, and they will still get thrown back into the filter for having sent out so many requests that they are tripping the sensor. This is a problem that only rears its head with Skype or viruses. Whatever Skype says about not being a Super node when behind a NAT-ed IP may not be entirely true.
I have actually even seen Skype somehow worm around the MAC filter system to where there was no option left but to deactivate the port for the number of requests that Skype was sending out was over running the server and no other request were getting through. This is as tragic as the ISP shutting down the hotel’s connection. I understand the necessity and need for easy and cheap ways to keep in contact with all of you business associates while abroad. I want the rest of you to understand that it is unfair and selfish to take all of the resources of the hotel for one user.
This is not such an important lesson for those who are in hotels with free access but when you get into places like the Penn Club in NY where the internet access is costing about as much as your average room at a Holiday Inn for one night, it becomes a very important thing to have everyone in the hotel actually share and play nice. If Skype can’t do this (Which in almost every case I have seen it can not.) then the problem is not with the hotel technology. The problem is with the Skype. Its easy to blame the hotel technology because you feel it has slighted you in some way, but it is the Skype that is giving you the finger behing your back while you shake your head at the hotel equipment and verbally assault me, the technician that says “Your killing the connection for the entire hotel.”